• 제목/요약/키워드: Nickel exposure

검색결과 80건 처리시간 0.024초

UVO 처리에 따른 NiOx 박막 및 페로브스카이트 태양전지 셀 특성 변화 (Effect of UVO Treatment on Optical and Electrical Properties of NiOx Thin Film and Perovskite Solar Cells)

  • 조수진;황재근;편도원;정석현;이솔희;이원규;황지성;최영호;김동환
    • Current Photovoltaic Research
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    • 제12권1호
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    • pp.1-5
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    • 2024
  • Perovskite solar cells have exhibited a remarkable increase in efficiency from an initial 3.8% to 26.1%, marking a significant advancement. However, challenges persist in the commercialization of perovskite solar cells due to their low stability with respect to humidity, light exposure, and temperature. Moreover, the instability of the organic charge transport layer underscores the need for exploring inorganic alternatives. In the manufacturing process of the perovskite solar cells' oxide charge transport layer, ultraviolet-ozone (UVO) treatment is commonly applied to enhance the wettability of the perovskite solution. The UVO treatment on metal oxides has proven effective in suppressing surface oxygen vacancies and removing surface organic contaminants. This study focused on the characterization of nickel oxide as the hole transport material in perovskite solar cells, specifically investigating the impact of UVO treatment on film properties. Through this analysis, changes induced by the UVO treatment were observed, and consequent alterations in the device characteristics were identified.

Concentration of heavy metals in shellfishes and health risk assessment from Korean coastal areas

  • Ka Jeong Lee;Eun Hye Kang;Minchul Yoon;Mi Ra Jo;Hong Sik Yu;Kwang Tae Son
    • Fisheries and Aquatic Sciences
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    • 제25권12호
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    • pp.626-636
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    • 2022
  • Shellfish are exoskeleton-bearing aquatic invertebrates that consume various organic and inorganic substances floating in seawater through filter feeding. Heavy metals are known as absorbed and accumulated in seawater. Some of the toxic heavy metals are highly accumulated in seawater, and exposure to them can cause a variety of risks to the human body. Since Koreans like to eat seafood, they are more likely to be exposed to contaminated seafood with heavy metals. In this study, nine types of heavy metals were analyzed on ten different shellfish species in the coastal area of South Korea. The risk assessment was also done on shellfish in which heavy metals were detected. Zinc (Zn) and copper (Cu) were identified at an average of 56.7 mg/kg (6.70 to 466 mg/kg) and 13.2 mg/kg (0.064 to 143 mg/kg), respectively. Lead (Pb) average of 0.208 mg/kg (0.000750 to 1.02 mg/kg), cadmium (Cd) average of 0.454 mg/kg (0.0388 to 1.56 mg/kg) and mercury (Hg) average of 0.0266 mg/kg (0.00548 to 0.174 mg/kg) were identified. Additionally, arsenic (As), chromium (Cr), nickel (Ni), and silver (Ag) were also identified as average concentrations of 4.02 (0.460 to 15.0 mg/kg), 0.167 (< limit of quantification [LOQ] to 0.820 mg/kg), 0.281 (< LOQ to 1.46 mg/kg), and 0.158 mg/kg (< LOQ to 1.15 mg/kg). The result indicates that the monitoring results of heavy metals in most shellfish satisfied the Korean standard. However, Pb and Cd have exceeded some foreign standards, such as the United States and the EU. The permissible human exposure calculated using the heavy metal intake and detection amount was lower than the Joint FAO/WHO Expert Committee on Food Additives human safety standard, and the risk of heavy metals from shellfish consumption was at an acceptable level.

차아염소산나트륨 용액과 고압증기멸균이 근관치료용 니켈-타이타늄 파일의 주기적 피로 파절에 미치는 영향 (CYCLIC FATIGUE OF THE SODIUM HYPOCHLORITE TREATED AND /OR STEAM AUTOCLAVED NICKEL-TITANIUM ENDODONTIC FILES)

  • 조혜영;정일영;이찬영;김의성
    • Restorative Dentistry and Endodontics
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    • 제33권1호
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    • pp.54-65
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    • 2008
  • 본 연구에서는 차아염소산나트륨 용액 및 고압증기멸균이 근관 치료용 Ni-Ti 파일의 주기적 피로 파절에 미치는 영향을 알아보고자 하였다. 파일 첨단 크기가 #30이고 .06 taper를 가지는 Hero $642^{(R)}$$K3^{(R)}$파일 70개를 10개씩 7개의 군으로 나누었으며, 6% 차아염소산나트륨 용액에 15분 (N15군), 30분 (N30군), 고압증기멸균은 $121\;^{\circ}C$의 온도, 0.12 MPa의 압력에서 20분간 시행하는 것을 일 회로 하여 5회 (H5군), 10회 (H10), 고압증기멸균 5회 후 차아염소산나트륨 용액 15분(H5N15), 고압증기멸균 10회 후 차아염소산나트륨 용액 30분 (H10N30) 처리 후 주기적 피로 파절 실험을 수행하여 파일이 파절될 때까지의 시간을 초 단위로 측정하였다. 대조군은 전처리를 하지 않고 주기적 피로 파절을 시행하였다. 95%의 신뢰도로 one-way analysis of varience를 이용하여 통계 처리하였으며, 다중 비교는 Tukey방법으로 분석하였다. 파일의 표면을 주사전자현미경으로 관찰하였다. 주기적 피로 파절에 소요된 시간은 Hero $642^{(R)}$는 각 군별로 유의할 만한 차이가 없었으며, $K3^{(R)}$는 N15, N30, H5N15군에서 대조군에 비해 짧은 시간이 소요된 것으로 나타났다 (p < 0.05). 주사전자 현미경에서 관찰했을 때 Hero $642^{(R)}$$K3^{(R)}$모두 N15, N30군에서 파일의 표면과 날이 부식이 되어 대조군에서 관찰된 일정 방향으로 배열된 정형화된 예리한 빗살무의가 부분적으로 파괴된 형태가 관찰되었으며, N15군에 비해 N30군에서 파일의 형태가 파괴된 양상이 뚜렷했으며, Hero $642^{(R)}$보다 $K3^{(R)}$가 심하게 부식된 양상이었다. H5군과 H10군에서는 $K3^{(R)}$ 파일은 날 부분이 무디어진 양상을 보였고, Hero $642^{(R)}$는 형태 파괴가 뚜렷하지 않았으나 H10군에서 표면의 빗살무늬가 약간 무디어진 양상을 보였다. H5N15군과 H10N30군에서는 그다지 뚜렷한 형태변화는 없었다. 본 연구 결과 $K3^{(R)}$파일을 사용 시에는 가능한 한 차아염소산나트륨에 적은 시간 노출시키는 것이 파일의 부식으로 인한 형태의 손상을 방지할 수 있고, 주기적 피로 파절에 걸리는 시간도 감소시킬 수 있을 것이다.

농작물중(農作物中) 중금속오염도(重金屬汚染度)와 1일섭취량(日攝取量) 및 허용기준설정(許容基準設定)에 관(關)한 연구(硏究) (A Study on the Crops Pollution with Heavy Metal)

  • 염용태;배은상;윤배중
    • Journal of Preventive Medicine and Public Health
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    • 제13권1호
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    • pp.3-12
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    • 1980
  • Certain heavy metals which may lead peoples to poisonous status are widely used in industry and their uses have been increasing along with rapid industrialization of this country. Such an increasement of metal uses aggravates the status of environmental pollution affecting foodstuffs which are the most important life supporting factor of animal and humanbeing. Concerning the safety measures to minimize food-borne transmission of such hazardous metals, surveillance is the backbone of them and probably more so with a potential problem such as intoxication. Theoretically, this surveillance should include the determination of levels of heavy metal toxicants in foods, the determination of food consumption patterns and typical total diet, and the estimation of total load of the metal contaminant from all sources of exposure including air, water, and occupational sources. In recent year, actually, such estimates on the total daily intake of some heavy metals from foods have been made in several developed countries and a wide variation of date by season, locality, and research method was recognized. Also in this country, this kind of research data is vitally needed to make up for the serious shortage or lack of references to estimate the total amount of heavy metal intake of the people. In this study, a modification model for estimation of the total daily intake of cadmium copper, nickel, zinc, and lead through foods was applied and concentrations of the above metals in crops cultivated in this country were measured with atomic absorption spectro photometer to get the following results. 1. Level of heavy metal concentration in crops Generally, the levels of such metals in essential crops such as rice, cucumber, radish. chinese cabbage, apple, pear, grape, and orange are similar or lower than those in Japan and other developed countries. By the way, a striking result on cadmium concentration was increasement of its concentration in rice from $0{\sim}0.035ppm$ in 1970 to 0.11ppm in this study. However, the value is still far below the. Japanese Permissible Lebel of 1.0ppm. 2. Estimation of total daily intake per capita from foods A new model for estimation was devised utilizing levels of metal concentration in foods, amount of food consumed, and other food factors. Based on the above method, the daily intake of cadmium was estimated to be $70.53{\mu}g/man/day$ in average which was as high as the Limit Value of ILO/WHO(up to $71.4{\mu}g/man/day$). Also, 3.89mg of Zinc, 1.65mg of cuppor, 0.32mg of lead were given as the total daily intake per capita by this research. 3. Efficacy of washing or skinning to decrease the amount of metals in crops After washing the crops sufficiently with commercial linear alkylate sulfonate, the concentration of heavy metals could be reduced to $50{\sim}80%$ showing decreasement rate of $20{\sim}50%$. Also, after skinning the fruits, decreasement rate of the heavy metal concentration shelved $0{\sim}50%$.

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미호종개 metallothionein 유전자의 구조 및 중금속 노출과 고온 자극에 대한 MT mRNA의 발현 특징 분석 (Gene Structure and Altered mRNA Expression of Metallothionein in Response to Metal Exposure and Thermal Stress in Miho Spine Loach Cobitis choii (Cobitidae; Cypriniformes))

  • 이상윤;남윤권
    • 한국어류학회지
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    • 제23권1호
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    • pp.61-69
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    • 2011
  • 멸종위기 어류 미호종개(Cobitis choii)로부터 중금속해독 단백질(metallothionein) 유전자를 분리, 클로닝하고 중금속 및 고온 스트레스에 대한 전사 발현 특정을 분석하였다. 미호종개 metallothionein는 gDNA, mRNA 및 아미노산 서열 모두에서 경골 어류 MT들의 구조적 특징을 잘 보전하고 있었으며, 생물정보분석을 통해 미호종개 MT 유전자 5'-upstream 영역은 중금속 조절, 면역 반응 및 온도 반응에 관여하는 다양한 전사 조절인자들의 부착 위치들을 포함하는 것으로 관찰되었다. 카드뮴(Cd), 구리(Cu), 니켈(Ni), 망간(Mn) 및 아연(Zn)을 이용한 침지 노출 실험(0.5 및 $1.0\;{\mu}M$; 24시간)에서 미호종개 MT mRNA 발현은 구리 및 카드뮴 처리군에서 가장 많이 유도되었고($1.0\;{\mu}M$ Cu 처리군에서 최대 10배), 망간 처리군에서는 비교적 적은 양의 MT 발현이 유도된 반면(2배), 아연 및 니켈 노출 군에서는 유의적인 MT 발현의 증감이 관찰되지 않았다. 또한 미호종개 MT 전사 발현은 고온 자극 ($25^{\circ}C$로부터 $31^{\circ}C$까지 증가)에도 민감하게 반응하는 것으로 나타나, $31^{\circ}C$ 도달시점에서 $25^{\circ}C$ 초기 MT mRNA 발현 수준보다 9배 높은 mRNA 발현이 관찰되었다. 본 연구 결과는 MT 기반의 유전자 발현 분석을 이용함으로써, 향후 멸종위기 어류 미호종개의 스트레스 반응 연구에 유용한 기초 자료를 제공할 수 있다고 기대된다.

Environment Parameters Affecting Heavy Metal Concentration in Sand Collected from Children Playground in Seoul Metropolitan Area

  • An, Hyunsun;Kim, Juhee;Hyun, Seunghun
    • 한국토양비료학회지
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    • 제46권3호
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    • pp.193-202
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    • 2013
  • The concentrations of heavy metals such as cadmium (Cd), chromium (Cr), copper (Cu), lead (Pb), zinc (Zn), nickel (Ni), and arsenic (As) in sand samples collected from selected children's playground and their correlation with environmental parameters, such as concentration of particulate matter in the atmosphere ($PM_{10}$), apartment age (> 5 years), clay and organic matter contents in sand samples, were analyzed. The average heavy metal concentration in samples was 0.040 mg $kg^{-1}$ for Cd, 0.200 mg $kg^{-1}$ for Cr, 1.75 mg $kg^{-1}$ for Cu, 15.1 mg $kg^{-1}$ for Ni, 3.42 mg $kg^{-1}$ for Pb, 66.7 mg $kg^{-1}$ for Zn and 0.750 mg $kg^{-1}$ for As, all of which were below the environmental regulatory level established by Korea Ministry of Environment. However, in the consideration of direct and oral exposure by children to playground sand, the risk of the concentration range in the samples might be greatly enhanced. Heavy metal concentration in samples collected from high $PM_{10}$ (> $70{\mu}gm^{-3}$) area was slightly greater than in samples from low $PM_{10}$ (< $70{\mu}gm^{-3}$), indicating the contribution of particulate matter in air phase to heavy metal concentration in playground sand samples. The concentrations of both Cd and Pb were the highest in apartments older than 21 years (0.050 mg $kg^{-1}$ and 5.28 mg $kg^{-1}$ for Cd and Pb respectively) and showed positive correlation with apartment age (p<0.01 and p<0.001 for Cd and Pb, respectively). Clay content in playground sands ranged 3.8~11.2% and was positively correlated with heavy metal concentration. Organic matter content was negligible (mostly < 0.1%) and showed poor correlation with heavy metal concentration. In conclusion, concentration of heavy metals in playground sand was found to be predominantly influenced by the apartment age and clay content in sand samples and supplemented by dust deposition of particulate matter ($PM_{10}$) from atmosphere.

Occupational Lung Cancer Surveillance in South Korea, 2006-2009

  • Leem, Jong-Han;Kim, Hwan-Cheol;Ryu, Jeong-Seon;Won, Jong-Uk;Moon, Jai-Dong;Kim, Young-Chul;Koh, Sang-Baek;Yong, Suk-Joong;Kim, Soo-Geun;Park, Jae-Yong;Kim, In-Ah;Kim, Jung-Il;Kim, Jung-Won;Lee, Eui-Cheol;Kim, Hyoung-Ryoul;Kim, Dae-Hwan;Kang, Dong-Mug;Hong, Yun-Chul
    • Safety and Health at Work
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    • 제1권2호
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    • pp.134-139
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    • 2010
  • Objectives: The lung cancer mortality in Korea has increased remarkably during the last 20 years, and has been the first leading cause of cancer-related deaths since 2000. The aim of the current study was to examine the time trends of occupational lung cancer and carcinogens exposure during the period 2006-2009 in South Korea, by assessing the proportion of occupational burden. Methods: We defined occupational lung cancer for surveillance, and developed a reporting protocol and reporting website for the surveillance of occupational lung cancer. The study patients were chosen from 9 participating university hospitals in the following 7 areas: Seoul, Incheon, Wonju, Daejeon, Daegu, Busan, and Gwangju. Results: The combined proportion of definite and probable occupational lung cancer among all lung cancers investigated in this study was 10.0%, 8.6%, 10.7%, and 15.8% in the years 2006 to 2009, respectively, with an average of 11.7% over the four-year study period. The main carcinogens were asbestos, crystalline silica, radon, polyaromatic hydrocarbons (PAHs), diesel exhaust particles, chromium, and nickel. Conclusion: We estimated that about 11.7% of the incident lung cancer was preventable. This reveals the potential to considerably reduce lung cancer by intervention in occupational fields.

인지기능 저하와 체내 중금속 10종 간 연관성 분석 (Association between Cognitive Decline and Ten Heavy Metals)

  • 임채린;이승호;서상민;박경원;김권민;최병무;김병권;임현주;홍영습
    • 한국환경보건학회지
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    • 제48권6호
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    • pp.306-314
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    • 2022
  • Background: Due to the rapid aging of the South Korean population, neurological diseases such as dementia are increasing. Many studies have reported that the incidence of dementia is associated with environmental factors along with age. Objectives: This study analyzed the association between cognitive function and ten heavy metals in the body: arsenic, aluminum, chromium, manganese, cobalt, nickel, iron, copper, zinc, and lead. Methods: From 2018 to 2019, a total of 120 participants who suffered from cognitive impairment were recruited for this study. Blood and urine samples were collected and analyzed for heavy metal concentrations using an inductively coupled plasma mass spectrometer. Demographic information was obtained through face-to-face questionnaires completed by a trained investigator. Cognitive function was evaluated with the Korean version of the Mini-Mental State Examination and the Korean version of the Boston Name Waiting Test. The associations between cognitive function scores and heavy metal concentrations were analyzed using multiple logistic regression analysis. Results: The average age of the 120 participants was 72.7 years, and 69.2% were female. The mean of the MMSE-K and K-BNT scores were 22.9 and 37.9, respectively. The geometric mean of aluminum (Al) was 8.42 ㎍/L. MMSE-K was associated with iron (Fe), but the significance was removed in the logistic regression based on 24 points. K-BNT was significantly associated with aluminum and the odds ratio for K-BNT above 38 decreased by 45% as the aluminum concentration increased. Conclusions: The association between aluminum and the K-BNT score indicated that aluminum is associated with language-related cognitive decline. Based on this result, further study will be conducted by considering co-exposure effects of heavy metals including aluminum.

생체의학에 적용 가능한 테이퍼형태의 금속성 마이코로니들 어레이의 개발 (A Development of Tapered Metallic Microneedle Array for Bio-medical Application)

  • 제우성;이정봉;김갑석;김경환;진병욱
    • 마이크로전자및패키징학회지
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    • 제11권2호
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    • pp.59-66
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    • 2004
  • 본 연구에서는 유리기판을 통한 SU-8의 이중층을 후면 노광을 통하여 테이퍼지고 속이 빈 형태의 마이크로니들 배열구조물을 만드는 새로운 방법을 제안하였으며 테이퍼지고 속이 빈 형태의 원형축의 Buckling현상에 관한 해석해를 구하였다. Pyrex 7740을 유리기판으로 사용하고 이중층 구조의 SU-8 막을 후면 노광으로 금형 구조물을 제작하는 공정을 개발하였다. $200\;{\mu}m$ 높이의 SU-8기둥들에서 $4.37{\sim}5^{\circ}$범위의 테이퍼 각도를 $400\;{\mu}m$ 높이의 SU-8기둥에서는 $3.08{\sim}4.48^{\circ}$범위 내의 테이퍼 각을 보여주고 있다. 후면 유체저장소와 가로세로 각각 10개의 테이퍼 형태로 전기도금된 니켈 마이크로니들 어레이를 유리 기판을 통해 이중층 구조의 SU-8막을 후면 노광하고. 니켈을 전기도금 함으로서 실현시켰다. $200\;{\mu}m$$400\;{\mu}m$ 높이의 벽두께 $10{\mu}m-20{\mu}m$ 및 내경 $33.6{\mu}m-101{\mu}m$인 마이크로니들 어레이를 제작하였다. 또한 $400\;{\mu}m$ 높이의 벽두께 $20\;{\mu}m$ 및 내경 $33.6\;{\mu}m$$3.08^{\circ}$의 테이퍼 각 마이크로니들의 임계 버클링힘은 1.8N이었다. 이 해는 차후의 테이퍼 형태의 마이크로니들의 설계시 많은 도움을 주리라 생각한다.

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국내 유통 식품용 플라스틱 기구 및 용기, 포장의 중금속 위해도 평가 (Risk Assessment of Heavy Metals Migrated from Plastic Food Utensils, Containers, and Packaging Distributed in Korea)

  • 이경연;김형수;장대용;구예지;이승하;여혜빈;윤지수;임경민;최재윤
    • 한국포장학회지
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    • 제28권3호
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    • pp.175-182
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    • 2022
  • 중금속은 첨가제 성분이나 오염으로 인해 식품용 플라스틱 기구 및 용기, 포장 제품에 유입되어 식품을 통해 인체로 노출될 수 있다. 따라서 본 연구에서는 독성을 가진 7종의 중금속(납, 카드뮴, 니켈, 크롬, 안티몬, 구리, 망간)을 선정하고 국내 유통되는 16재질 137개 제품들에서의 이행량을 파악하여 위해도 평가를 수행하였다. 대상 검체들은 4% 초산을 식품모사용매(70℃, 30분)로 적용하여 이행시험을 수행하였다. 동시분석을 위해 유도결합플라즈마 질량분석법(ICP-MS)을 적용했으며 선형성, 검출 한계(LOD), 정량 한계(LOQ), 회수율, 정밀도를 측정하고 확장불확도를 산출하여 정량결과의 신뢰성을 확보하였다. 모니터링 결과, 전체적으로 불검출 (ND) ~ 8.76 ± 11.87 ㎍/L의 수준으로 검출되었으며, 대부분이 평균 1 ㎍/L 미만의 미량으로 확인되었다. 또한 안티몬이 PET 재질에서 다른 재질들에 비해 통계적으로 유의하게 높게(p < 0.05) 측정되었다. 마지막으로 위해도를 평가한 결과, 국내 유통되는 제품들의 중금속들은 인체안전기준 대비 모두 안전한 수준으로 유지되고 있는 것을 확인하였다.